Question

A man standing on a platform 225 m long notices that a train travelling at a uniform speed
passes him in 6 s and passes by the platform in 21 s. Find (1) the length of the train and
(ii) the speed of the train.​

Answer 1

Step-by-step explanation:

Length of train = L

length of platform= 225m

time taken by train to cross the man = 6s

distance travelled by train to cross the man = L

time taken to cross platform= 21s

distance travelled by train to cross the platform= (L+225)m

So, in order to travel {(L+225) - (L)}m, train takes (21 - 6) second

Or train travels 225m in 15 second

speed of train = 225/15 = 15 m/s

Length of train = speed of train × time taken to cross the man = 15 × 6 = 90m